EP0916928A1 - Capteur de vitesse de rotation - Google Patents

Capteur de vitesse de rotation Download PDF

Info

Publication number
EP0916928A1
EP0916928A1 EP98923060A EP98923060A EP0916928A1 EP 0916928 A1 EP0916928 A1 EP 0916928A1 EP 98923060 A EP98923060 A EP 98923060A EP 98923060 A EP98923060 A EP 98923060A EP 0916928 A1 EP0916928 A1 EP 0916928A1
Authority
EP
European Patent Office
Prior art keywords
constant
current
voltage
comparison
power supply
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP98923060A
Other languages
German (de)
English (en)
Other versions
EP0916928A4 (fr
Inventor
Hiroshi Shimamura
Shinjiro Ueda
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Panasonic Corp
Original Assignee
Matsushita Electric Industrial Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Matsushita Electric Industrial Co Ltd filed Critical Matsushita Electric Industrial Co Ltd
Publication of EP0916928A1 publication Critical patent/EP0916928A1/fr
Publication of EP0916928A4 publication Critical patent/EP0916928A4/fr
Withdrawn legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
    • G01D5/00—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable
    • G01D5/12—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means
    • G01D5/14—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage
    • G01D5/142—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage using Hall-effect devices
    • G01D5/147—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage using Hall-effect devices influenced by the movement of a third element, the position of Hall device and the source of magnetic field being fixed in respect to each other
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01P—MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT
    • G01P3/00—Measuring linear or angular speed; Measuring differences of linear or angular speeds
    • G01P3/42—Devices characterised by the use of electric or magnetic means
    • G01P3/44—Devices characterised by the use of electric or magnetic means for measuring angular speed
    • G01P3/48—Devices characterised by the use of electric or magnetic means for measuring angular speed by measuring frequency of generated current or voltage
    • G01P3/4802—Devices characterised by the use of electric or magnetic means for measuring angular speed by measuring frequency of generated current or voltage by using electronic circuits in general

Definitions

  • the present invention relates to a rotational speed-detecting device provided with a signal processing circuit for detecting a variation of magnetic leakage flux produced by a rotating or moving multi-polar magnet or a variation of magnetic leakage flux produced between a gear of magnetic moving body and a fixed magnet by utilizing a magneto-electric element, and for executing a voltage-current conversion by shaping waveform of the detected signal.
  • a detecting element of the prior art for detecting rotation of a gear is a magnetic coil 102 coupled with a bias magnet 103, as shown in Fig. 6, so as to gain an induced voltage across the coil by detecting a variation of magnetic flux density due to a change of magneto-resistance produced by projections and depressions of a rotating gear 101.
  • the rotating gear 101, the bias magnet 103 and the magnetic coil 102 are considered as a generator, and a magnitude of the induced voltage depends upon a rotational speed, and a signal is detectable with two lines.
  • it is a simple and inexpensive structure, it has a fundamental problem in that the induced voltage decreases at low speed.
  • a ferromagnetic magnet-resistance element 104 is used as a detecting element in combination with a signal processing circuit 105 for superposing a rectangular wave current on a power supply line by a constant-current drive, as shown in Fig.7.
  • It utilizes a pair of current-miller circuits for the constant-current drive, in which a current of one of the current-miller circuits is kept flown at all the time, while a current of the other current-miller circuit is turned on and off by an output signal at a midpoint of the ferromagnetic magneto-resistance element 104 of a half bridge, so as to produce a rectangular wave current, and superposes the rectangular wave current on the power supply line in order to reduce a signal output line and to convert three lines into two lines.
  • Detecting elements suitable for this purpose are so-called magneto-electric elements of positional detection type, such as a Hall element, a ferromagnetic magneto-resistance element, and a semiconductor magneto-resistance element.
  • the semiconductor magneto-resistance element in particular, is one of the most suitable for detecting a rotational gear, since it produces a high detection signal voltage. If a magneto-electric element of positional detection type is used for the rotational sensor, two current supply lines and one signal output line, for a sum of three lines are generally needed to constitute the circuit.
  • a rotational sensor capable of detecting an extremely low speed with two lines is desirable, however, in consideration of compatibility with a magnetic coil, reduction of a vehicle weight, effective usage of a cab space, etc.
  • a two-line system in a rotational speed-detecting device of the positional detection type detects a variation of magnetic leakage flux produced by a rotating or moving body with a magneto-electric element, and superposes a rectangular wave current on the power supply line after signal processing, so as to reduce a number of a signal output line by way of calculating the number of rotations or the amount of movement of the rotating or moving body with a computer by detecting a voltage across a resistor inserted in the power supply line at a power supply side.
  • This method requires to reduce absolute values and a relative difference of a high current value and a low current value of the rectangular wave as small as possible, in order to reduce a power consumption of the entire circuit and to hold down heat generation of the circuit elements as little as possible.
  • the smaller it is to keep an absolute current value of the rectangular wave current the more important a preciseness of the current value of the rectangular current waveform is, in order to reliably recognize the high current value and the low current value of the rectangular wave. For this reason, a method has been used in the past in which a current consumption of an entire signal processing circuit is controlled by using a constant-current circuit.
  • MR ferromagnetic magneto-resistance elements
  • a first object of the present invention is to provide a rotational speed-detecting device capable of obtaining a rectangular wave current having a good current accuracy even under variations of ambient temperature (-40 °C to 150 °C) and power supply voltage (8 V dc to 16 V dc).
  • a second object of the present invention is to provide a rotational speed-detecting device, of which circuit structure can be simplified, and is of a two-line type, yet it is capable of detecting an extremely low speed.
  • a rotational speed-detecting device of the present invention includes: a sensor means including a detecting unit, which connects magneto-electric elements of positional detection type in series, and a comparison voltage generating unit, which connects comparison voltage resistors in series and is connected in parallel with the detecting unit; a comparison means connected to each of a midpoint of the detecting unit and a midpoint of the comparison voltage generating unit constituting the sensor means; a constant-voltage control means provided between a supply side of power supply line and the sensor means for supplying constant voltage to the sensor means; a constant-voltage generating means provided between the supply side and a return side of the power supply line for supplying constant voltage to the constant-voltage control means; and a constant-current means provided between the supply side and the return side of the power supply line for determining a constant current flown by the constant-voltage generating means between the supply side and the return side, wherein a rectangular wave current is superposed and flown in the power supply line by controlling a constant
  • the above structure is able to provide a rotational speed-detecting device of two-line type, which is capable of superposing a rectangular wave current having a small absolute value and relative difference in current value of the rectangular wave currents onto the power supply line, with an excellent accuracy of the rectangular wave current, even if the power supply voltage changes and if an ambient temperature varies.
  • the magneto-electric elements of positional detection type in the detecting element unit and the comparison voltage resistor unit for comparing a waveform detected by the magneto-electric elements of positional detection type which can be a major factor of dispersion in current value of the rectangular wave current, are driven with a constant voltage.
  • an output of the SMR decreases with a low supply voltage since the output varies in proportion to the supply voltage, dispersion of current value caused by a variation of resistance value due to temperature, which is a major factor of the dispersion in current value of the rectangular wave current, can be suppressed by driving the SMR with a low constant voltage, taking advantage of a characteristic of the SMR of which detection output is quite large.
  • a composite resistance of the two SMRs that constitute a half bridge changes from 1.6 k ⁇ to 80 k ⁇ , for instance, in a temperature variation range of -40 °C to 150 °C.
  • the Y increases monotonously relative to the variable X, and every Y values fall between a minimum Y value when the X is at the minimum and a maximum Y value when the X is at the maximum.
  • a dispersion of the detecting unit can be regulated for a constant current in an accuracy of ⁇ 1.8375/2 mA, if it is driven with 3 V dc.
  • the constant voltage stabilization can prevent a variation of the comparison voltage associated with a variation in resistance value of the SMR along with a movement of the moving body, and makes a noise margin larger than the one that is driven with a constant current, and enables the signal detecting unit to stabilize a current.
  • dispersion of current in the detecting unit can be restricted to a small value by driving it with a low constant voltage, taking advantage of a characteristic of the SMR of which detection signal output is larger than other detecting elements of positional detection type.
  • V0 ( ⁇ R/R) ⁇ Vd/(2 - ⁇ R/R)
  • a sensor means 11 includes a detecting unit, which connects magneto-electric elements of positional detection type in series, and a comparison voltage generating unit, which connects comparison voltage resistors in series and is connected in parallel with the detecting unit.
  • a comparison means 12 connects to each of a midpoint of the detecting unit and a midpoint of the comparison voltage-generating unit constituting the sensor means 11.
  • a numeral 13 represents a constant-voltage control means provided between a supply side Vcc of a power supply line and the sensor means 11 for supplying constant voltage to the sensor means 11.
  • a constant-voltage generating means 14 is provided between the supply side Vcc and a return side VR of the power supply line for supplying constant voltage to the constant-voltage control means 13.
  • the constant-current means 15 is provided between the supply side Vcc and the return side VR of the power supply line for determining a constant current flown by the constant-voltage generating means 14 between the supply side and the return side.
  • the constant-voltage generating means 14 functions to generate a constant voltage even when the power supply voltage fluctuates, and it includes a field effect type transistor (hereinafter referred to as "FET") Q3, a Zener diode D1, dividing resistors R8, R9 and R10, and a resistor R11.
  • the constant-current means 15 functions to switch the rectangular wave current between a high current value and a low current value by an on-and-off output signal of a comparator IC1, and it includes the Zener diode D1, the dividing resistors R8, R9 and R10, a transistor Q2 and resistors R5, R6 and R7.
  • the constant-voltage control means 13 operates to drive the comparison-voltage resistors and the SMRs, and it includes the Zener diode D1, the dividing resistors R8, R9 and R10, a transistor Q1 and a .resistor R4.
  • the detecting unit functions to detect a variation of magnetic flux density associated with rotation of a gear and to produce a comparison voltage, and it includes the SMRs (SMR1 and SMR2) and resistors R1 and R2.
  • the comparison means 12 compares the detected signal with the comparison voltage, converts it into a pulse signal, and it includes the comparator IC1 and a hysteresis resistor R3.
  • the resistors R4, R5 and R11 function as power consumption restricts resistors for the transistors Q1 and Q2, and the FET Q3.
  • the sensor means 11 which includes the comparison-voltage generating unit and the detecting unit that is placed between a bias magnet 3 and a gear 1, as shown in Fig. 3, and it detects a variation of magnetic flux density associated with rotation of the gear 1.
  • the comparison means 12, the constant-voltage control means 13, the constant-voltage generating means 14, the constant-current means 15, etc. are constructed on a flexible substrate 7 as a signal processing circuit 5 for outputting through a terminal 8 which also serves for the power supply.
  • a circuit operation of the signal processing circuit of the exemplary embodiment of the present invention is described in detail.
  • a variation of leakage flux due to movement of a moving body of magnetic material or a multi-polar magnet is differentially detected by two resistors R1 and R2, which are separately positioned at a predetermined space, and the SMR 1 and SMR2 constituting a half bridge, and the comparator IC1 compares the comparator IC1 with a comparison voltage produced by a resistance-dividing method, and an output of an open-collector of the comparator IC1 is turned on and off.
  • the SMRs of the detecting unit and the comparison-voltage generating unit are driven by a constant-voltage circuit stabilized with a voltage determined by the Zener diode D1.
  • the comparator IC1 contains an IC, which is stabilized with a constant current, and is connected directly to the power supply line.
  • a bias current of the Zener diode D1 is supplied by the FET Q3.
  • the SMRs have a resistance-temperature characteristic in which a composite resistance of approximately 8 k ⁇ at the normal temperature (25 °C) changes to approximately 80 k ⁇ at a low temperature (-40°C) and approximately 1.6 k ⁇ at a high temperature (150°C).
  • Vd driving voltage value
  • Vd the driving voltage value of constant current
  • the constant-current means 15 possesses a constant-current value determined by an emitter voltage and an emitter resistor of the transistor Q2 that operates with a voltage determined by the Zener diode D1, and an output of the comparator IC1 having an open collector is connected to a part of the emitter resistor.
  • the power supply line is superposed with a low current value of the rectangular wave current consisting of the constant current determined by the emitter voltage and the emitter resistor of the transistor Q2 of the constant-current means 15 and currents flowing to the detecting unit, the comparison means 12 and the constant-voltage generating unit 14, and, when the open collector of the comparator IC1 is high (conductive state), the power supply line is superposed with a high current value of the rectangular wave current by dividing the emitter current of the transistor Q2 of the constant-current means 15.
  • the emitter resistor for the transistor Q2 is adjusted of its resistance value by trimming, etc. in order to fix a current value of the rectangular wave current at a predetermined value.
  • the constant-voltage generating unit 14 supplies a bias current of the Zener diode D1 with a drain current of the FET Q3, and the FET Q3 is biased between a gate and a source in a manner to minimize the drain current relative to temperature changes, the drain current becomes nearly constant through a wide range of the supply voltage variation and a wide range of temperature change, so that an excellent constant-voltage characteristic is attained against the supply voltage variation.
  • a temperature characteristic of a Zener voltage Vz and a temperature characteristic of a base-emitter voltage Vbe of the transistors Q1 and Q2 in the constant-current means 15 and the constant-voltage control means 13 cancel with each other, individual emitter voltages indicate approximately constant values relative to the variation in temperature through the servicing temperature range.
  • the rectangular current waveform with a maximum current dispersion of ⁇ 2 mA or less is obtainable for a maximum value of 20 mA and a minimum value of 10 mA of the rectangular wave current in a supply voltage range of 8 V to 16 V at the servicing temperature of -40°C to 150°C, with a structure composed of the sensor means 11 having the detecting unit of the SMRs and the voltage generating unit of the comparison voltage resistors, the comparison means 12, the constant-current means 15 by an emitter current of the transistor Q2, and the constant-voltage generating means 14 of the FET and the Zener diode.
  • the circuit consists of one FET, one Zener diode and two transistors, so that a simple structure with a total of four active elements enables an accurate voltage-current conversion and a reduction into a two-line circuit.
  • the constant-current means 15 and the constant-voltage control means 13 employ the transistors Q1 and Q2 respectively, they can commonly use the transistor Q1, instead, as shown in Fig. 4, and divide it with emitter resistors R14 and R15. This is suitable if current values of the rectangular wave current are small when it is on and off.
  • the FET Q3 of the constant-voltage generating means 14 may be replaced by a resistor 16, as shown in Fig. 5.
  • a stable constant voltage is obtainable even under fluctuation of the power supply voltage Vcc, by using a Zener diode capable of generating a constant voltage at a low current bias value.
  • the present invention is able to provide the following effects through an extent of a wide range of servicing temperature (-40 °C to 150 °C) and a wide range of power supply voltage (8 V dc to 16 V dc), even when using a magnetic detecting element of which resistance value changes significantly by temperature.

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Transmission And Conversion Of Sensor Element Output (AREA)
  • Electronic Switches (AREA)
EP98923060A 1997-06-02 1998-06-01 Capteur de vitesse de rotation Withdrawn EP0916928A4 (fr)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
JP143638/97 1997-06-02
JP9143638A JPH10332722A (ja) 1997-06-02 1997-06-02 回転速度検出装置
PCT/JP1998/002403 WO1998055834A1 (fr) 1997-06-02 1998-06-01 Capteur de vitesse de rotation

Publications (2)

Publication Number Publication Date
EP0916928A1 true EP0916928A1 (fr) 1999-05-19
EP0916928A4 EP0916928A4 (fr) 2010-08-25

Family

ID=15343432

Family Applications (1)

Application Number Title Priority Date Filing Date
EP98923060A Withdrawn EP0916928A4 (fr) 1997-06-02 1998-06-01 Capteur de vitesse de rotation

Country Status (4)

Country Link
US (1) US6144197A (fr)
EP (1) EP0916928A4 (fr)
JP (1) JPH10332722A (fr)
WO (1) WO1998055834A1 (fr)

Families Citing this family (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6277737B1 (en) * 1998-09-02 2001-08-21 Micron Technology, Inc. Semiconductor processing methods and integrated circuitry
EP1183501B1 (fr) * 1999-05-18 2003-10-15 Continental Teves AG & Co. oHG Capteur de torsion de flanc
US6640451B1 (en) * 2000-01-28 2003-11-04 Visteon Global Technologies, Inc. System and method for sensing the angular position of a rotatable member
DE10158052A1 (de) * 2001-11-27 2003-06-05 Philips Intellectual Property Anordnung zum Bestimmen der Position eines Bewegungsgeberelements
DE10210184A1 (de) * 2002-03-07 2003-09-18 Philips Intellectual Property Anordnung zum Bestimmen der Position eines Bewegungsgeberelements
US7265539B2 (en) * 2005-06-09 2007-09-04 Ford Motor Company Calibration of a hall effect sensor
US8143884B2 (en) * 2006-05-12 2012-03-27 Nxp B.V. Current interface with a blocking capacitor attached to an additional pin
US7595633B2 (en) * 2007-02-08 2009-09-29 Honeywell International Inc. Velocity measurement using magnetoresistive sensors
JP5013254B2 (ja) * 2007-07-04 2012-08-29 株式会社デンソー 車両用計器回路
US8369988B2 (en) * 2011-01-11 2013-02-05 Schlagel, Inc. Grain distribution apparatus and method
US9291479B2 (en) * 2011-08-10 2016-03-22 GM Global Technology Operations LLC Plastic speed target wheel and method of manufacture
JP5529203B2 (ja) 2011-09-21 2014-06-25 シャープ株式会社 光センサおよび電子機器
JP5472761B2 (ja) * 2012-02-17 2014-04-16 株式会社デンソー 位置検出装置
US9599506B2 (en) 2012-10-12 2017-03-21 Sharp Kabushiki Kaisha Optical sensor and electronic apparatus with a first auxiliary current and current amplifier
EP3243083A1 (fr) * 2015-01-08 2017-11-15 Sondex Wireline Limited Détecteur de déséquilibre de courant cc sensible et procédé d'étalonnage
CN104977423B (zh) * 2015-06-19 2017-12-01 中国航空工业集团公司上海航空测控技术研究所 一种磁电式转速传感器
CN112147976B (zh) * 2020-08-12 2023-03-28 上汽通用五菱汽车股份有限公司 轮速模拟系统和方法

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5168274A (en) * 1990-10-17 1992-12-01 Olympus Optical Co., Ltd. Position detector device
JPH05332787A (ja) * 1992-05-28 1993-12-14 Hitachi Metals Ltd Ｍｒセンサ信号変換回路
US5455510A (en) 1994-03-11 1995-10-03 Honeywell Inc. Signal comparison circuit with temperature compensation
JPH09196943A (ja) * 1996-01-19 1997-07-31 Honda Motor Co Ltd 車両用回転速度センサ

Also Published As

Publication number Publication date
US6144197A (en) 2000-11-07
EP0916928A4 (fr) 2010-08-25
JPH10332722A (ja) 1998-12-18
WO1998055834A1 (fr) 1998-12-10

Similar Documents

Publication Publication Date Title
US6144197A (en) Rotational speed device with magneto-electric elements
EP0505499B1 (fr) Alimentation en puissance regulee a bifurcation
JP2574659B2 (ja) 高出力電圧スイングを有する温度補償された磁気抵抗センサ回路
JPS6318761B2 (fr)
JPH0675247B2 (ja) 空気流量検出装置
JP3153729B2 (ja) 非接触型センサ装置
EP0449443A1 (fr) Anémomètre à résistance électrique
US4868909A (en) Signal shaping circuit utilizing a magneto-resistor in a voltage divider circuit
US4922126A (en) Circuit for shaping a measurement-signal voltage into a square-wave signal
JPH074486Y2 (ja) 磁気センサの取付構造
JP3209519B2 (ja) 電子回路
JP3561173B2 (ja) 非接触型センサ
US6188226B1 (en) Electric potential sensor
JP2569595B2 (ja) センサ信号入力装置の接触抵抗検出装置
US6208176B1 (en) Adaptive driver circuit for semiconductor magnetoresistors
GB2198559A (en) Voltage reference circuit for a vehicle ignition system
JP3182908B2 (ja) 半導体式センサ回路装置
JPH05102549A (ja) 集積化磁気抵抗センサ
JPH08205577A (ja) ブラシレスモータ
JPS629076A (ja) 電磁弁駆動装置
JPH0810799Y2 (ja) 変流形センサー
JP2508992Y2 (ja) 電気式回転計測器のメ―タアッセンブリの入力回路
JPH0729456Y2 (ja) エンコーダ回路
JPH11206191A (ja) モータ制御回路
JP3028750B2 (ja) 交差コイル式メータ

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): DE FR GB IT

17P Request for examination filed

Effective date: 19990527

RAP1 Party data changed (applicant data changed or rights of an application transferred)

Owner name: PANASONIC CORPORATION

A4 Supplementary search report drawn up and despatched

Effective date: 20100726

17Q First examination report despatched

Effective date: 20101216

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 20140103